With the rapid advancement of automotive electronics, there has been an increasing quantity of electrical control units in modern vehicles. These electrical control units can be divided into powertrain system control (e.g., engine control and transmission control), chassis control (e.g., ABS system) and body control. Body Control Module (“BCM”) is mainly used for improving the driving convenience and ride comfort. BCM system covers a wide range including lamp control, doors/windows control, seat control, air-condition control, instrument panel control, etc, and realizes performance and safety of a vehicle together with other systems. With the development of automation control, more and more body electrical equipment is used on an automotive body, which forces BCM to control more units. More information are shared between each electrical equipments, thus a strengthened data communication function is required for a BCM. Therefore, a single centralized BCM is hard to fulfill these huge functions, which leads to a trend of bus and network type of BCM. Lin (Local interconnect network) bus control method is also used for BCM communication, especially for BCM for simple control requirement of small communication traffic and slow communication rate, e.g., auto wiper and anti-pinch system.
Till now, more and more vehicles are equipped with panorama sunroofs. A panorama sunroof generally includes a sunroof glass and a sunshade. Due to the limitation of size and location, a sunshade glass need some cooperative action to enable the full open/close action of a panorama sunroof. In prior art, a sunroof glass and a sunshade are controlled respectively by individual Sunroof Controller Unit (“SCU”). Each SCU drive the panorama sunroof by Lin bus control. When a sunroof glass is being opened or closed, the corresponding SCU drive the sunshade through Lin bus, so as to avoid the position conflict of the sunroof glass and the sunshade. Thus, the Lin bus system is complex. The stability of the system is poor and the cost is high. Additionally, workers in a factory usually assemble wrong units into the sunroof glasses or sunshades because the SCU of them are of same shapes. Hence there is a desire for a sunroof controller which has a simple yet accurate control mechanism to control the air/gas volume ratio, preferably over a wide range.